Letters : Super gas

Seymour M. Hersh, in Chemical and Biological Warfare (Panther 1970),
describes CN, CS and DM, the three US military riot control agents then
available. CN is (-chloroacetophenone (C6H5COCH2Cl),
and is the mildest of the three. CS, which is ortho
-chlorobenzalmalonitrile (ClC6H4CHC(CN)2), was
developed to be faster-acting and more toxic than CN. DM, the nastiest (“not
approved for use in operations where deaths are not acceptable”) is the German
First …